Hi, I'm the author of the piece. What you describe, while astute, isn't what's going on here, because at the level these agreements are being made, the French intelligence services don't care that the NSA is spying on French nationals. There's no negotiation to be made: they simply want to maintain their existing capacity, but have been required to give it legal cover by the greater recent visibility of mass surveillance. In fact, among intelligence services of putative allies, having another friendly nation spy on your nationals grants you a potential advantage, since it means you can bypass domestic restrictions by simply trading intel with them. (It's also one of the reasons why bilateral agreements would be undermined, and difficult to initiate. They would also preserve the idea that some classes of innocent users are fair game for mass surveillance, while others deserve protection.)

France's surveillance advantage comes from its access to submarine cables rather than local servers. That's the information it will be collecting, and potentially trading with others.

Much of the problem here, I'd note, comes from not separating the defensive and offensive components of the intelligence services. Whatever you belief is the proportionate level of surveillance of a population, it's clear that an institution whose job was to protect the assets and personal data of a nation's population would have a very different attitude to letting others spy on its comma traffic than one which was primarily concerned with aggressively investigating other nations. Politicians are therefore hearing policy proposals from only one side of a debate. That's why they think that backdoors would help and not harm national security, and why they think spying on the rest of the world without oversight won't erode their own citizens' privacy.